This invention relates to emergency type service for telephone customers served by cable systems.
Telephone service has become a vital service. It is required for access to the emergency services offered through xe2x80x9c911xe2x80x9d emergency systems. It is a vital link to elderly people whose relatives check on their health by calling them periodically. In particular, one of the important characteristics of older telephone systems is that they work even in the presence of a power failure in an area. During some of the more notorious blackouts of recent years, people were still able to communicate through the telephone network.
The integrity of the telephone network in the presence of power failures is being compromised by the use of cable systems for providing telephone service. Users of these cable systems require the use of a working modem which is powered by commercial power. Customers served by cable systems, therefore, have the option of doing without vital telephone service when power fails, using cellular telephones to bypass the cable system, or receiving back-up service from a conventional wire-line Public Switched Telephone Network of the type that provides its own power, and will serve customers even if those customers are not receiving commercial power.
A problem of prior art systems which provide back-up through the use of the wire-line Public Switched Telephone Network (PSTN), is that the back-up service uses expensive facilities to solve a problem, (power failure), that occurs relatively infrequently.
Applicants have analyzed this problem, and have sought to find additional uses for the back-up wire-line PSTN. In accordance with their invention, they have made an advance over the prior art by disclosing a system for utilizing the back-up PSTN to simultaneously access all idle telephones in a home or commercial establishment having a plurality of telephones associated with a plurality of telephone numbers; the back-up PSTN has a single telephone number for reaching all of these telephones. If a caller calls, using the telephone number of the back-up wire-line PSTN, that caller, with or without power failure, will be connected to the telephones of the called household or commercial establishment in such a way that all telephones will ring and any one of them can be answered. Advantageously, this arrangement allows individual access to the telephones through the cable system, and group access to the telephones through the wire-line Public Switched Telephone Network.
In addition, the telephones are equipped with a key to allow them to originate calls to the PSTN for emergencies.